Switched outlet system and method

ABSTRACT

A method, performed by a transmit module coupled to a switched outlet and a receive module coupled to a continuously-powered outlet, for providing switched power to an electrical device from the continuously-powered electrical outlet, comprising detecting, by the transmit module, power applied to the switched outlet as a result of a switch being placed into an “on” position, in response to detecting the power applied to the switched outlet, transmitting, by the transmit module, a first signal to the receive module, receiving, by the receive module, the first signal, and in response to receiving the first signal, causing a switch to apply power to the electrical device from the continuously-powered electrical outlet.

BACKGROUND I. Field of Use

The present application relates to the field of home electrical devices.More specifically, the present application relates to a system andmethod for providing switched power to an electrical device from acontinuously-powered electrical outlet.

II. Description of the Related Art

Millions of homes have been constructed in the United States over thepast several decades that include electrical outlets, also referred toas electrical sockets. Electrical outlets are devices that allowelectrically operated equipment to be connected to an alternatingcurrent (AC) power supply in a building. Electrical outlets differ involtage and current ratings, shape, size and types of connectors. Thetypes used in each country are set by national standards, some of whichare listed in the IEC technical report TR 60083 Plugs and socket-outletsfor domestic and similar general use standardized in member countries ofIEC.

Electrical outlets for single phase domestic, commercial and lightindustrial purposes generally provide either two or three electricalconnections to the supply conductors. Two-pin sockets normally provideneutral and line connections, both of which carry current and aredefined as live parts. Neutral is usually very near to earth potential,usually being earthed either at the distribution board or at thesubstation. Line (also known as phase or hot, and commonly, buttechnically incorrectly, as live) carries the full supply voltagerelative to the neutral (and to earth). Three-pin sockets provide, inaddition, a protective earth connection for exposed metal parts of anappliance. If internal insulation should fail, a short-circuit to theearthed exposed metal parts will hold them at a low potential, andshould operate fuses or circuit breakers to isolate the faulty appliancefrom the supply. Depending on the supply system, some sockets may havetwo line connections, each at significant voltage to earth and without aneutral pin; for example, a split phase system may have 240 V betweenline connections each at 120 V with respect to earth ground; but asingle-phase receptacle connected to a three-phase system may have, forexample, 208 V between contacts and only 120 V between each contact andearth ground.

While many home electrical outlets are always energized, others may bewired to become energized only when an associated wall switch isactivated. Such an outlet is referred to herein as a “switched outlet”.Typically, a toggle switch is placed near an entry door of a room andwired to activate a particular outlet in the room. This arrangement isadvantageous when the outlet selected for control by the switch is in alocation where, for example, a lamp may be plugged in, allowing a userto light the room simply by activating the switch as the user enters theroom. However, more often than not, the switched outlet is not in anarea of the room where it is convenient to locate a plug-in electricallamp. In this case, the benefit of having a switch near the entry dooris defeated.

SUMMARY

The embodiments described herein relate to various embodiments of asystem and method for providing switched power to an electrical devicefrom a continuously-powered electrical outlet. In one embodiment, asystem is described, comprising system for providing switched power toan electrical device from a continuously-powered electrical outlet,comprising a transmit module coupled to a switched outlet for detectingthe presence or absence of power from the switched outlet, and fortransmitting a first signal upon detection of the presence of power anda second signal upon detection of the absence of power, and a receivemodule coupled to the continuously-powered electrical outlet in the sameroom as the switched outlet, the receive module comprising a plug forcoupling the receiver module to the continuously-powered electricaloutlet, a socket for providing switched power to an electrical device, areceiver for receiving the first and second signals; and first circuitryconfigured to receive power from the plug, to provide the power from theplug to the socket upon receipt of the first signal and for removing thepower from the socket upon receiving the second signal.

In another embodiment, a method is described, performed by a transmitmodule coupled to a switched outlet and a receive module coupled to acontinuously-powered outlet, for providing switched power to anelectrical device from the continuously-powered electrical outlet,comprising detecting, by the transmit module, power applied to theswitched outlet as a result of a switch being placed into an “on”position, in response to detecting the power applied to the switchedoutlet, transmitting, by the transmit module, a first signal to thereceive module, receiving, by the receive module, the first signal, andin response to receiving the first signal, causing a switch to applypower to the electrical device from the continuously-powered electricaloutlet.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, advantages, and objects of the present invention willbecome more apparent from the detailed description as set forth below,when taken in conjunction with the drawings in which like referencedcharacters identify correspondingly throughout, and wherein:

FIG. 1 is a perspective view of a room in a residential setting,featuring a transmit module and a receive module in accordance with theteachings herein;

FIG. 2 is a perspective view of one embodiment of the transmit module asshown in FIG. 1;

FIG. 3 is a perspective view of one embodiment of the receive module asshown in FIG. 1;

FIG. 4 is a functional block diagram of one embodiment of transmitmodule as shown in FIGS. 1 and 2;

FIG. 5 is a functional block diagram of one embodiment of receive moduleas shown in FIGS. 1 and 2;

FIG. 6 is a functional block diagram of another embodiment of a transmitmodule;

FIG. 7 is an illustration of another embodiment of the transmit moduleas shown in FIGS. 1 and 2, comprising discreet components;

FIG. 8 is an illustration of another embodiment of the receive module asshown in FIGS. 1 and 2, comprising discreet components; and

FIG. 9 is a flow diagram illustrating one embodiment of a methodperformed by the transmit module and the receive module as shown in FIG.1 to control power to an electrical device via the switch as shown inFIG. 1.

DETAILED DESCRIPTION

The present application relates to a system for control of an electricaloutlet. The system comprises a transmit module plugged into a switchedelectrical outlet and a receive module plugged into a powered outlet,typically in the same room as the switched electrical outlet. When poweris applied to the switched outlet, typically by operating a wall switchin the same room as the switched outlet, the transmit module detectsenergization of the switched outlet and, in response, transmits a signalto the receive module. The receive module receives the signal from thetransmit module and, in response, causes a socket of the receive moduleto become energized with power from the powered outlet. In this way, anypowered outlet in a room can be controlled by the wall switch withouthaving to purchase an after-market light switch or engage the servicesof an electrician.

FIG. 1 is a perspective view of a room 100 in a residential setting,comprising wall switch 102, transmit module 104 plugged into switchedelectrical outlet 106, and receive module 108 plugged intocontinuously-powered electrical outlet 110. An electrical device 112,shown as a floor lamp, is plugged into receive module 108.

Wall switch 102 comprises any standard, household switch for controllingelectrical devices such as lights in a room or, in this case, switchedelectrical outlet 106. Switched electrical outlet 106. switchedelectrical outlet 106 is de-energized, un-powered, de-activated, orsimply “off” when switch 102 is in a first, “off” position, andenergized, powered, activated or “on” when switch 102 is placed into asecond “on” position, typically by manipulating a toggle mechanism thatforms part of switch 102. When switched electrical outlet 106 is active,household voltage of typically 110-120 VAC is available at switchedelectrical outlet 106. Typically, switched electrical outlet 106comprises two outlets, each available for receiving a respective plugfrom a standard electrical device, such as a light, a toaster, a vacuumcleaner, or any common household appliance, for example. When such anelectronic device is plugged into switched electrical outlet 106, theelectrical device can be turned “on” or “off” via switch 102, as poweris applied and removed from switched electrical outlet 106 as switch 102is turned on and off.

However, oftentimes, it is desirable for switch 102 to control an outletother than switched electrical outlet 106. For example, room 100 may befurnished with a bed, a nightstand and a floor lamp for providing lightto room 100, where the floor lamp is positioned in proximity tocontinuously-powered electrical outlet 110. It may be desirable,therefore, to control the floor lamp using switch 102. However, becausethe floor lamp is located in proximity to continuously-poweredelectrical outlet 110, it may not be possible or desirable to plug thefloor lamp into switched electrical outlet 106, due to the relativelylong distance between the two. This problem is solved by the embodimentsdescribed herein, as follows.

Transmit module 104 is mechanically and electrically coupled to switchedelectrical outlet 106, i.e., plugged into switched electrical outlet106, where it receives power from switched electrical outlet 106 whenswitch 102 is placed into an “on” position and powered off when switch102 is placed into an “off” position. Receive module 108 is mechanicallyand electrically coupled to continuously-powered electrical outlet 110,and electrical device 112 is mechanically and electrically coupled to anoutlet provided by receive module 108. Continuously-powered electricaloutlet 110 comprises an “always on” electrical outlet and providescontinuous 110-120 VAC power to electrical devices. The outlet(s)provided by receive module 108 are normally de-energized, i.e., power isnot provided to the outlet(s).

When switch 102 is placed from the “off” position to the “on” position,transmit module 104 becomes energized as a result of switched electricaloutlet 106 becoming energized by switch 102. Upon energization, transmitmodule 104 transmits a signal that is received by receive module 108,either wirelessly, through household wiring that electrically couplesswitched electrical outlet 106 to continuously-powered electrical outlet110 (commonly known as “powerline communications”) via switch 102, orboth. The signal indicates that switch 102 has been placed into the “on”position and that switched electrical outlet 106 has been energized.

When receive module 108 receives the signal transmitted by transmitmodule 104, receive module 108 causes power from continuously-poweredelectrical outlet 110 to be provided to its outlet(s), thereby providingpower to electrical device 112. In this way, electrical device 112 maybe turned on or off via switch 102, as if electrical device 112 wasplugged into switched electrical outlet 106.

Similarly, when switch 102 is placed from the “on” position to the “off”position, transmit module becomes de-energized as a result of switchedelectrical outlet 106 becoming de-energized by switch 102. However, justbefore de-energization, transmit module 104 detects the loss of powerfrom switched electrical outlet 106 and in response, transmits a secondsignal before becoming de-energized. The second signal indicates thatswitch 102 has been placed into the “off” position and that switchedelectrical outlet 106 has been de-energized.

When receive module 108 receives the second signal transmitted bytransmit module 104, receive module 108 cuts the power fromcontinuously-powered electrical outlet 110 to electrical device 112,turning 112 off.

It should be understood that additional receive modules could be used inroom 100, as well as in other rooms or outdoors, in conjunction with asingle transmit module 104. For example, upon activation, transmitmodule 104 can transmit a first “on” signal to receive module 108,turning a light on in room 100, while simultaneously turning on outdoorlighting via a second receive module located in another part of thehouse, and turn on an amplifier for playing music. In this case, eachreceive module is generally “paired” with a single transmit module sothat only paired receive modules take action when “on” and “off” signalsare transmitted by a paired transmit module.

When two or more receive modules are paired with a single transmitmodule, each receive module may comprise an emitter for transmittingacknowledgement signals to their paired transmit module when theyreceive “on” and/or “off” signals from a transmit module. Suchacknowledgment may be particularly important when controlling electricaldevices that are not in room 100, out of sight of a user. In thisembodiment, transmit module 104 may comprise one or more indicators,such as LEDs or the like, each assigned to a particular

FIG. 2 is a perspective view of one embodiment of transmit module 104.In this embodiment, transmit module 104 comprises a body 200, twoelectrical prongs 202, a receiver 204, and three LEDs 206 or similarlight-emitting devices. Typically, transmit module 104 is designed tosmall and lightweight so as to not be noticeable when it coupled toswitched electrical outlet 106. In one embodiment, body 200 is twoinches in width and length, and an inch thick. Prongs 202 comprise two,metal prongs that are sized and shaped to be inserted into a typical,household electrical power outlet, and may be of different size and/orshape to differentiate between neutral and “hot” or power. Prongs 202may additionally comprise a third metal protrusion, sized and shaped forinsertion into a ground receptacle in electrical outlets so equipped.Receiver 204 is an optional feature, comprising a sensor that converts asensed condition into electrical energy, so that transmit module 104 maydetermine whether a light was turned on after transmit module 104transmits a signal to receive module 108, instructing receive module 108to provide power to electrical device 112. This feature will bedescribed in greater detail herein.

FIG. 3 is a perspective view of one embodiment of receive module 108. Inthis embodiment, receive module 108 comprises a body 300, two electricalprongs 302, emitter 304 and at least one electrical outlet 306.Typically, receive module 108 is designed to small and lightweight so asto not be noticeable when it coupled to continuously-powered electricaloutlet 110. In one embodiment, body 300 is two inches in width andlength, and an inch thick. Although these dimensions are the same astransmit module 104, they need not be. Prongs 302 comprise two, metalprongs that are sized and shaped to be inserted into a typical,household electrical power outlet, and may be of different size and/orshape to differentiate between neutral and “hot” or power. Prongs 302may additionally comprise a third metal protrusion, sized and shaped forinsertion into a ground receptacle in electrical outlets so equipped.Emitter 304 is an optional feature, comprising one or more light bulbs,LEDs, IR transmitters, or ultrasonic transducers, designed to send anacknowledgement signal from receive module 108 to transmit module 104 ofsuccessful receipt of signals transmitted by transmit module 104.Further details of this feature are described later herein. Electricaloutlet 306 mimics a standard electrical outlet, sized and shaped toreceive power prongs from electrical device 112, either with or withouta ground prong.

FIG. 4 is a functional block diagram of one embodiment of transmitmodule 104. Specifically, FIG. 4 shows processor 400, memory 402,receiver 204, transmitter 404, power supply 406, electrical plug 202,energy storage device 408 and LEDs 206. It should be understood that notall of the functional blocks shown in FIG. 4 are required for operationof transmit module 104 (for example, receiver 204), and that thefunctional blocks may be connected to one another in a variety of waysother than what is shown in FIG. 4.

Processor 400 is configured to provide general operation of transmitmodule 104 by executing processor-executable instructions stored inmemory 402, for example, executable computer code. Processor 400typically comprises a general purpose microprocessor or microcontroller,manufactured by well-known companies such as Intel Corporation of SantaClara, Calif., Atmel of San Jose, Calif., and STMicroelectronics basedin Geneva, Switzerland, selected based on size, cost and performancecharacteristics.

Memory 402 comprises one or more information storage devices, such asRAM, ROM, EEPROM, UVPROM, flash memory, SD memory, XD memory, or othertype of electronic, optical, or mechanical information storage device.Memory 402 is used to store the processor-executable instructions foroperation of transmit module 104 as well as any information used byprocessor 200, such as information pertaining to whether receive module108 successfully received one or more transmissions from transmit module104.

In one embodiment, receiver 204 comprises a light or sound transducerthat converts light or sound into electrical energy for use by processor400. As such, receiver 204 may comprise an IR receiver, a LED receiver,or an ultrasonic receiver. In another embodiment, receiver 204 maycomprise an RF receiver or a powerline circuitry to receive anddemodulate wireless or wired signals transmitted from transmit module104. Such circuitry is well known in the art and may comprise BlueTooth,Wi-Fi, RF, or powerline circuitry, among others.

Transmitter 404 comprises circuitry to transmit signals to receivemodule 108 via RF, IR, ultrasonic, or powerline technology, all of whichare well known in the art.

Power supply 406 comprises an AC-to-DC converter for providinglow-voltage, DC power to processor 400, memory 402, transmitter 404 andreceiver 204. Typically, power supply 406 converts household 110-120 VACpower to 3.3, 5, 12, or some other DC voltage. An input of power supply406 is mechanically and electrically coupled to one of the prongs 202.Power supply 406 provides DC voltage(s) to the electrical components oftransmit module 104 when switched electrical outlet 106 is energized viaswitch 102. When switched electrical outlet 106 is de-energized viaswitch 102, the DC voltage(s) provided by power supply 406 are reducedto approximately zero volts over a very short time period, such as 50milliseconds, but not instantaneously.

Energy storage device 408 is used to store energy from power supply 406or directly from plug 202 to provide power to the components of transmitmodule 104 to ensure that at least one signal is transmitted whenswitched electrical outlet 106 loses power as a result of switch 102being placed into the “off” position. In this embodiment, charge storagedevice 408 comprises a capacitor or an inductor. In another embodiment,a rechargeable battery is used. In yet another embodiment, anon-rechargeable battery is used, but is not charged by power supply 406or plug 202. In an embodiment where energy storage device 408 comprisesa capacitor or an inductor, the capacitor or inductor is selected tostore enough charge to allow processor 400 to transmit at least onesignal to receive module 108 in order for receive module 108 to cutpower to electrical device 112.

LEDs 206 comprise one or more light-emitting devices, such as LEDs, LCDsor the like, which provides an inexpensive status of one or moreelectrical devices that are controlled by transmit module 104. The LEDsare off when transmit module 104 is off, i.e., switch 102 is in an “off”position. Each LED becomes illuminated by processor 400 when processor400 receives an acknowledgement from each electrical device that it iscontrolling. For example, if three receive modules have been paired withtransmit module 104, processor 400 may assign each one to a particularLED 206. Then, when acknowledgements are received by transmit module 104after transmitting an “on” signal to the three receive modules,processor 400 causes a corresponding LED to become illuminated. Thisprovides a useful visual indication as to which electrical devices wereactually turned on by the “on” signal. When an “off” signal istransmitted by transmit module 104, the LEDs may remain powered by oneor more other energy storage devices, such as a capacitor or batteryuntil an “off” acknowledgement is received from the one or more transmitdevices, prior to transmit module 104 losing power as a result of switch102 being placed into the “off” position. In another embodiment, energystorage device 408 is sized to accommodate both transmission of an “off”signal, as well as to process “off” acknowledgement(s) and de-activatethe LEDs as acknowledgements are received from the receive modules(s).Although the LEDs will be extinguished after the energy storage deviceis exhausted, this embodiment will, nevertheless, provide an instantfeedback mechanism to a user who has just placed switch 102 into the“off” position.

FIG. 5 illustrates a functional block diagram of one embodiment ofreceive module 108. Specifically, FIG. 5 shows processor 500, memory502, receiver 504, emitter 304, electrical plug 302, switch 506 andelectrical socket 306. It should be understood that not all of thefunctional blocks shown in FIG. 4 are required for operation of transmitmodule 104 (for example, receiver 204), and that the functional blocksmay be connected to one another in a variety of ways other than what isshown in FIG. 4. No power supply is shown, for purposes of clarity, asthe components shown in FIG. 5 may be powered by a power supply similarto power supply 406 or by a rechargeable or non-rechargeable battery, asis well known in the art. In the case of a power supply, unlike powersupply 406, power is never switched off at continuously-poweredelectrical outlet 110. Thus, receive module 108 is continuously powered.Emitter 304, plug 302 and socket 306 have previously been described.

Processor 500 is configured to provide general operation of receivemodule 108 by executing processor-executable instructions stored inmemory 502, for example, executable computer code. Processor 500typically comprises a general purpose microprocessor or microcontroller,manufactured by well-known companies such as Intel Corporation of SantaClara, Calif., Atmel of San Jose, Calif., and STMicroelectronics basedin Geneva, Switzerland, selected based on size, cost and performancecharacteristics.

Memory 502 comprises one or more information storage devices, such asRAM, ROM, EEPROM, UVPROM, flash memory, SD memory, XD memory, or othertype of electronic, optical, or mechanical information storage device.Memory 502 is used to store the processor-executable instructions foroperation of receive module 108 as well as any information used byprocessor 200, such as information pertaining to whether receive module108 successfully received one or more transmissions from transmit module104.

Receiver 504 comprises well-known circuitry for receiving signalstransmitted by transmit module 104. Receiver 504 may comprise an RFreceiver, an IR receiver, an ultrasonic receiver, a powerline receiver,or some other receive circuitry that is known in the art.

Switch 506 comprises a relay, transistor or other switch that providespower from plug 302 (i.e., 110-120 VAC) to socket 306 and, hence,electrical device 112, upon a signal from processor 500 and, likewise,cuts power to socket 306 upon another signal from processor 500. Thisprocess is detailed below.

FIG. 6 is a functional block diagram of another embodiment of a transmitmodule 600. In this embodiment, transmit module 600 is plugged into acontinuously powered electrical outlet rather than a switched outlet,and further provides an electrical socket for plugging an electronicdevice into transmit module 600. When the electrical device that isplugged into transmit module 600 is turned on, transmit module 600detects that the electrical device has been turned on, as evidenced, forexample, by an increase in current draw through transmit module 600, orby some other means. Upon detection that the electrical device has beenturned on, transmit module transmits an “on” signal to one or morereceive modules, as described previously. When transmit module 600determines that the electrical device has been turned off, it transmitsan “off” signal to the one or more receive modules, also describedpreviously.

FIG. 6 illustrates processor 600, memory 602, receiver 604, transmitter606, power supply 608, electrical plug 610, electrical socket 612, LEDs614 and power detector 616. Some or all of these components may beimplemented as discreet components, integrated circuits, or acombination of both. It should be understood that not all of thefunctional blocks shown in FIG. 6 are required for operation of transmitmodule 600 (for example, receiver 204 or LEDs 608), and that thefunctional blocks may be connected to one another in a variety of waysother than what is shown in FIG. 6. Processor 600, memory 602, receiver604, transmitter 606 power supply 608, electrical plug 610, and LEDs 614are the same or similar to like items shown in FIG. 4 and theirdescriptions are not repeated here. Electrical socket 612 is similar toelectrical outlet 106 on receive module 108.

As shown, power from a continuously-powered outlet is provided viaelectrical plug 610 to socket 612 for powering one or more electricaldevices. Power detector 616 detects when one or these electrical deviceshas been turned on by a user. In one embodiment, power detectorcomprises a resistor sized to accommodate 15 or 20 amps of 110-120 VACpower at a relatively low ohm value, such as 1 ohm, for providing avoltage drop that may be measured by processor 600 in order to determinewhen a sudden increase in current has occurred, for example when anelectrical device plugged into socket 612 is turned on. In otherembodiments, one or more of transformers, relays, transistors, etc. maybe used to provide such a change in current draw, measurable byprocessor 600. Other ways to determine when an electrical device hasbeen turned on (or off) are well known in the art. In one embodiment,receiver 604 may be used as a feedback mechanism to determine when alight, for example, has been turned on, as explained above with respectto transmit module 104. When processor 600 determines that theelectrical device plugged into socket 612 has been turned on, processor600 causes transmitter 606 to transmit an “on” signal to one or morereceive modules, indicating that a user has turned on an electricaldevice and for the receive modules to apply power to their respectiveelectrical devices. When power detector 616 determines that theelectrical device plugged into socket 612 has been turned off, processor400 causes transmitter 606 to transmit an “off” signal, which causes theone or more receive modules to cut power to their respective electricaldevices.

FIG. 7 is an illustration of another embodiment of transmit module 104,comprising discreet components. Plug 202 provides switched power tostep-down circuitry 700, typically a transformer that converts the110-120 VAC from plug 302 to a lower voltage, such as 5-10 VAC. Thestepped-down voltage is provided to detection circuitry 702, whichdetermines when switched electrical outlet 106 becomes energized andde-energized as a result of switch 102 being placed into the “on” and“off” positions, respectively. FIG. 6 illustrates one embodiment of suchdetection circuitry, comprising a low pass filter and comparator thatcompares the filtered, stepped-down voltage from step-down circuitry 700and provides a signal to transmitter 704 to transmit the first signal.Transmitter 704 may comprise an integrated circuit specially designed toprovide low cost, low power transmitting capabilities. The first signalmay comprise a continuous wave signal at a particular, predeterminedfrequency indicative of switch 102 being turned to the “on” position, amodulated, digital sequence, or some other predetermined waveformindicative of switch 102 begin turned on. When switch 102 is turned“off”, detection circuitry 702 determines the loss of power, again bycomparing the voltage from step-down circuitry 700 to the referencevoltage, and provides a signal to transmitter 704, causing transmitter704 to transmit the second signal, which may comprise a differentfrequency, amplitude, phase or modulated digital sequence than the firstsignal.

FIG. 8 is an illustration of another embodiment of receive module 108,comprising discreet components. Receiver 800 receives the first andsecond signals transmitted by transmit module 104, demodulates thesignals, and provides an output to detection circuitry 802, in thisexample, a simple comparator circuit. In this embodiment, when the firstsignal is received, receiver 800 provides a signal to detectioncircuitry, for example a fixed voltage. Detection circuitry 802 detectsthe voltage from receiver 800 and provides a voltage to switch 804, forexample, a transistor or relay, which causes switch 804 to close,providing power to socket 306. When receiver 800 receives the secondsignal, receiver 700 may provide a different voltage to detector 802,and detector 802 detects this voltage and provides another voltage toswitch 804, causing switch 804 to cut power to socket 306.

FIG. 9 is a flow diagram illustrating one embodiment of a methodperformed by transmit module 104 and receive module 108 to control powerto electrical device 112 via switch 102. It should be understood that insome embodiments, not all of the steps shown in FIG. 9 are performed. Itshould also be understood that the order in which the steps are carriedout may be different in other embodiments. The method is performed inaccordance with the configuration shown in FIG. 1, with transmit module104 plugged into switched electrical outlet 106, receive module 108plugged into continuously-powered electrical outlet 110, and electricaldevice 112 plugged into receive module 108. It should also be understoodthat although the method refers to transmit module 104 and receivemodule 108 in the embodiments shown in FIGS. 4 and 5, respectively, thesteps could alternatively be performed by the discrete components shownin FIGS. 6 and 7.

At block 900, switch 102 is in an “off” position, and no power ispresent at switched electrical outlet 106. Transmit module 104 ispowered off due to the lack of power from switched electrical outlet106.

At block 902, switch 102 is placed into an “on” position by a user. As aresult, switched electrical outlet 106 becomes energized with 110-120VAC, and transmit module 104 is powered on from the power supplied byswitched electrical outlet 106 and power supply 406.

At block 904, in response to being powered on, processor 400 causestransmitter 404 to transmit a first signal to receive module 108. Inanother embodiment, the first signal is transmitted in response toprocessor 400 determining that power has been applied to switchedelectrical outlet 106. This embodiment is used when transmit module 104is powered by a battery and does not rely on switched electrical outlet106 for operational power. The first signal indicates that switch 102was placed into the “on” position, and for receive module 108 to providepower from continuously-powered electrical outlet 110 to electricaldevice 112. The first signal may comprise one or more digital packetshaving an identification code that uniquely identifies receive module108. Such an identification code could be generated using a “pairingprocess” between receive module 108 and transmit module 104, aswell-known in the art. The identification code is used to ensure thatthe first signal controls only transmit module 104 that is located inthe same room as transmit module 104, so that other transmit module104's that may be installed in other rooms are not influenced by thefirst signal transmitted by transmit module 104.

The first signal may further comprise a predetermined digital sequence,indicative of switch 102 being placed into the “on” position. In anotherembodiment, the first signal may comprise, simply, a modulated orunmodulated sinusoidal waveform, transmitted using well-known RFtechniques such as frequency modulation or amplitude modulation.

In another embodiment, processor 400 does not transmit the first signalas soon as power is applied to switched electrical outlet 106. Rather,transmission is delayed until energy storage device 408 is sufficientlypowered to additionally transmit a second signal, instructing receiver108 to cut power to electrical device 112. This embodiment is useful toprevent a condition where switch 102 is turned from “off” to “on” andthen back to “off” very quickly. Without a delay, processor 400 maycause transmission of the first signal, but unable to transmit thesecond, “turn off” signal if energy storage device had not had time tocharge to the point of being capable of powering processor 400 and/ortransmitter 404 sufficiently to transmit the second signal. The delay istypically set to avoid a perceptible delay between turning switch 102“on” and when electrical device 112 becomes activated, but enough topower at least processor 400 and/or transmitter 404 sufficiently totransmit the second signal. In one embodiment, a hardware or softwarecounter is used to enable transmission a predetermined time afterelectrical switched outlet 106 becomes energized, such as 200milliseconds. In another embodiment, one or more discreet components maybe used, such as a capacitor and resistor combination, where thecapacitor becomes sufficiently charged after 200 milliseconds of appliedpower. Other embodiments are well known to those skilled in the art.

At block 906, the first signal is received by receive module 108, viareceiver 504, demodulated and provided to processor 500.

At block 908, processor 500 determines that the first signal wasreceived. In one embodiment, processor 500 compares a digital sequencein the first signal and compares the digital sequence to arepresentative digital sequence stored in memory 502, indicating thatswitch 102 has been placed into the “on” position. If a match isdetermined, processor 500 determines that the first signal was received.

At block 910, in response to determining that the first signal wasreceived, processor 500 causes switch 506 to close, allowing power fromplug 302 to be provided to socket 306, thus energizing socket 306 and,thus, electrical device 112.

At block 912, in one embodiment, also in response to determining thatthe first signal was received, processor 500 causes emitter 304 totransmit an acknowledgement to transmit module 104, indicatingsuccessful receipt of the first signal. The acknowledgment signal maycomprise one or more digital packets having an identification code thatuniquely identifies transmit module 104, from the pairing processmentioned earlier. In one embodiment, emitter 304 comprises an infra-red(IR) transmitter and transmit module 104 receives the acknowledgementsignal via receiver 504, in this case, an IR receiver.

At block 914, if processor 400 fails to receive the acknowledgementsignal transmitted by transmit module 104 at block 912 within apredetermined time period, such as 1 second, processor 400 may causetransmitter 404 to re-transmit the first signal at least one more time.In another embodiment, processor 400 causes transmitter 404 tore-transmit the first signal until the acknowledgement signal isreceived.

In another embodiment, where receive module 108 does not transmit anacknowledgement signal (i.e., receive module 108 is not configured withemitter 304), acknowledgement of whether the first signal was receivedsuccessfully may be determined by processor 400, via receiver 204,receiving light from electrical device 112. This feature may be usefulwhen a room is dim or dark, and receive module 108 is used to control alight source. In this embodiment, receiver 406 is sensitive to visiblelight from electrical device 112, and when light is received by receiver204 from electrical device 112, processor 400 determines that the firstsignal was successfully received by receive module 108. If processor 400fails to receive a signal from receiver 204, indicating reception oflight from electrical device 112, processor 400 may re-transmit thefirst signal one or more times, until such signal is received fromreceiver 204, indicating that electrical device 112 was turned on.

At block 916, switch 102 is placed into an “off” position by a user,causing switched electrical outlet 106 to become de-energized.

At block 918, processor 400 detects a reduction in the voltage frompower supply 406 or directly from switched electrical outlet 106 viaplug 202. Processor determines that switch 102 was placed into the “off”position when the voltage from switched electrical outlet 106 or powersupply 406 drops by a predetermined threshold, such as when the voltagefrom switched electrical outlet 106 or power supply 406 drops by 30%.

At block 920, in response to determining that switch 102 has been placedinto the “off” position, processor 400 causes transmitter 404 totransmit a second signal indicating that switch 102 has been placed intothe “off” position. The second signal may comprise a different digitalsequence than the first signal, or it may be the same. If the same,processor 500 simply toggles switch 506 each time that a signal isreceived. In one embodiment, energy storage device 408 provides enoughresidual power to at least processor 400 and transmitter 404 in orderfor processor 400 to cause transmitter 404 to transmit the secondsignal.

At block 922, the second signal is received by receive module 108, viareceiver 504, demodulated and provided to processor 500.

At block 924, processor 500 determines that the second signal wasreceived. In one embodiment, processor 500 compares a digital sequencein the second signal and compares the digital sequence to arepresentative digital sequence stored in memory 502, indicating thatswitch 102 has been placed into the “off” position. If a match isdetermined, processor 500 determines that the second signal wasreceived.

At block 926, in response to determining that the second signal wasreceived, processor 500 cuts the power from plug 302 to socket 306,i.e., causes switch 506 to open, de-energizing socket 306 and, thus,electrical device 112.

At block 928, in one embodiment, also in response to determining thatthe second signal was received, processor 500 causes emitter 304 totransmit an acknowledgement to transmit module 104, indicatingsuccessful receipt of the second signal. The acknowledgment signal maycomprise one or more digital packets the same as the acknowledgementsignal sent at block 912, or it may be different.

The methods or algorithms described in connection with the embodimentsdisclosed herein may be embodied directly in hardware or embodied inprocessor-readable instructions executed by a processor. Theprocessor-readable instructions may reside in RAM memory, flash memory,ROM memory, EPROM memory, EEPROM memory, registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An exemplary storage medium is coupled to the processor suchthat the processor can read information from, and write information to,the storage medium. In the alternative, the storage medium may beintegral to the processor. The processor and the storage medium mayreside in an ASIC. The ASIC may reside in a user terminal. In thealternative, the processor and the storage medium may reside as discretecomponents.

Accordingly, an embodiment of the invention may comprise acomputer-readable media embodying code or processor-readableinstructions to implement the teachings, methods, processes, algorithms,steps and/or functions disclosed herein.

While the foregoing disclosure shows illustrative embodiments of theinvention, it should be noted that various changes and modificationscould be made herein without departing from the scope of the inventionas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the embodiments of the inventiondescribed herein need not be performed in any particular order.Furthermore, although elements of the invention may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

We claim:
 1. A system for providing switched power to an electricaldevice from a continuously-powered electrical outlet, comprising: atransmit module coupled to a switched outlet for detecting the presenceor absence of power from the switched outlet, and for transmitting afirst signal upon detection of the presence of power and a second signalupon detection of the absence of power; and a receive module coupled tothe continuously-powered electrical outlet in the same room as theswitched outlet, the receive module comprising: a plug for coupling thereceiver module to the continuously-powered electrical outlet; a socketfor providing switched power to an electrical device; a receiver forreceiving the first and second signals; and first circuitry configuredto receive power from the plug, to provide the power from the plug tothe socket upon receipt of the first signal and for removing the powerfrom the socket upon receiving the second signal.
 2. The system of claim1, wherein the transmit module comprises: a plug for plugging thetransmit module into the switched outlet and for receiving power fromthe switched outlet; a transmitter coupled to the second circuitry fortransmitting the first and second signals; and second circuitry coupledto the plug and the transmitter, configured to detect the presence andabsence of power from the switched outlet via the plug and, in response,transmit the first or second signal.
 3. The system of claim 2, furthercomprising: an energy storage device for storing a quantity ofelectrical energy from the switched outlet, the quantity of electricalenergy at least enough to transmit the second signal after the switchedoutlet becomes de-energized.
 4. The system of claim 3, where the energystorage device comprises a capacitor.
 5. The system of claim 2, whereinthe transmitter and the second circuitry are powered by the power fromthe switched outlet when the switched outlet is energized.
 6. The systemof claim 5, wherein the transmitter and the second circuitry arede-powered when the switched outlet is de-energized, and the secondsignal is transmitted just prior to the transmitter becomingde-energized after the switched outlet becomes de-energized.
 7. Thesystem of claim 2, further comprising: an infra-red transmitter coupledto the first circuitry, wherein the first circuitry causes the infra-redtransmitter to transmit an acknowledgement signal indicative of thereceive module receiving the first signal from the transmit module; andan infra-red receiver coupled to the second circuitry; wherein thecircuitry causes the transmitter to re-transmit the first signal whenthe circuitry fails to receive the acknowledgment signal aftertransmitting the first signal.
 8. The system of claim 1, wherein thetransmit module further comprises: a light detector coupled to thecircuitry for detecting the presence or absence of light from theelectrical device; and wherein the circuitry causes the transmitter tore-transmit the first signal at least a second time if the lightdetector indicates the absence of light after the first signal isinitially transmitted.
 9. A method, performed by a transmit modulecoupled to a switched outlet and a receive module coupled to acontinuously-powered outlet, for providing switched power to anelectrical device from the continuously-powered electrical outlet,comprising: detecting, by the transmit module, power applied to theswitched outlet as a result of a switch being placed into an “on”position; in response to detecting the power applied to the switchedoutlet, transmitting, by the transmit module, a first signal to thereceive module; receiving, by the receive module, the first signal; andin response to receiving the first signal, causing a switch to applypower to the electrical device from the continuously-powered electricaloutlet.
 10. The method of claim 9, further comprising: detecting, by thetransmit module, power removed from the switched outlet as a result ofthe switch being placed into an “off” position; in response to detectingthe power removed from the switched outlet, transmitting, by thetransmit module, a second signal to the receive module; receiving, bythe receive module, the second signal; and in response to receiving thesecond signal, causing the switch to cut power from to the electricaldevice from the continuously-powered electrical outlet.
 11. The methodof claim 10, further comprising: providing power to the transmit modulefrom the switched outlet when power is applied to the switched outlet;and providing power to the transmit module from an energy storage devicefor a predetermined time period after the power is removed from theswitched outlet.
 12. The method of claim 10, further comprising:transmitting, by the receive module, an acknowledgment signal to thetransmit module in response to receiving the first signal.
 13. Themethod of claim 12, further comprising: re-transmitting, by the transmitmodule, the first signal when the transmit module fails to receive theacknowledgement signal within a predetermined time period fromoriginally transmitting the first signal.
 14. The method of claim 10,further comprising: receiving, by the transmit module, light produced bythe electrical device after transmission of the first signal; andre-transmitting, by the transmit module, the first signal when thetransmit module fails to receive the light within a predetermined timeperiod from originally transmitting the first signal.
 15. The method ofclaim 11, wherein transmitting the first signal occurs when power hasbeen removed from the switched outlet and the transmit module is poweredby the energy storage device.